Self-study
A politician can neither be reelected nor avoid censure by his or her colleagues if that politician is known to be involved in any serious scandals. ███████ █████████ ███████████ ████ ████ ███ ████ █████ ██ ██ ████████ ██ █ ██████████ ████ ██████ ████ █ ███████ ████████ █████ ███████████ ████ █████████ ███ ██ ██████████
Summary
If a politician is known to be involved in a serious scandal, then she will not be reelected and will be censured by her colleagues.
Some prominent politicians are now known to be involved in a serious scandal.
They won’t be reelected.
Notable Valid Inferences
They’ll also be censured by their colleagues.
6.
If the statements above are ███ █████ █████ ███ ██ ███ █████████ ██████████ ████ ████ ██ █████
a
The prominent politicians ██████ ██████ ███████ ██ █████ ███████████
Must be true. The politicians referred to here are known to be involved in a serious scandal. So they must be censured by their colleagues. 
b
If there had ████ ██ ████████ ███ █████████ ███████████ █████ ██ ██████████
Could be false. This confuses sufficient with necessary. Denying the sufficient condition (“known to be involved in serious scandal”) doesn’t tell us whether the necessary condition (”not reelected”) is also denied. Even politicians who aren’t known to be involved in serious scandals can still fail to be reelected.
c
No politician is ████████ ██████ ██ ██ ███ ██ █████ ██ ██ ████████ ██ █ ███████ ████████
Could be false. This says that if a politician is censured, she must be known to be involved in a serious scandal. This swaps sufficiency for necessity. “Censured by colleagues” isn’t sufficient for “known to be involved in serious scandal.” As far as we know, politicians can be censured even without the fuss of a scandal.
d
The prominent politicians █████████ █████████ ████ ███ ██████████ ████ ██████ ███ ████████
Could be false. Nothing in the stimulus suggests that they benefited. The only things we know about the consequences of the conspiracy are that it turned into a serious scandal and it became known, which satisfies the sufficient condition and so triggers two necessary outcomes, neither of which sounds very beneficial.
e
Some politicians who ███ ████████ ██ ██████████ ████████████ █████ █████████ ███ ████████
Could be false. This is about politicians involved in unknown scandalous conspiracies. But we only know about politicians involved in known scandalous conspiracies. It’s possible that every time a politician is involved in a scandalous conspiracy, it becomes known.