The stimulus tells us some bridges that do need rehab aren’t suspension bridges, so (A) attempts to take the contrapositive of that “some” claim, which isn’t allowed.

Working from a different angle, the stimulus tells us all suspension bridges are not-faulty, but none of the stimulus’ claims take us from “not faulty” to [anything]. In other words, “not faulty” never appears in a claim’s sufficient condition, so it’s a dead end as we try to build a conditional chain from suspension to not-rehab.

The stimulus tells us some bridges that need rehab aren’t suspension bridges, but that doesn’t mean other bridges that need rehab are suspension bridges – “some” can include “all.” That is, the claim above leaves room for all rehab bridges to be non-suspension bridges.

Working from a different angle, the stimulus tells us all suspension bridges are not-faulty, but none of the stimulus’ claims take us from “not faulty” to [anything]. In other words, “not faulty” never appears in a claim’s sufficient condition, so it’s a dead end as we try to build a conditional chain from suspension to rehab.

This puts a “some” claim before an “all” claim, which is a valid argument form:

English
Some faulty bridges were built in the 50s.*
All bridges built in the 50s need rehab.
________
Some faulty bridges need rehab.

Logic
Faulty ←some→ 50s*
50s → Rehab
________
Faulty ←some→ Rehab

*“Some” claims are reversible.

This must be false. The stimulus’ first sentence tells us all 50s bridges need rehab.

The double-negative is annoying – (E) just says “Some faulty bridges are suspension bridges.”

This must be false. The stimulus’ last sentence tells us no suspension bridges are faulty.