I am confused about why D is wrong. Is the below explanation correct?

The causal statement his friends make is:

Driving minivans/larger sedans --> lower accident rates

In order for this to be a necessary/sufficient mix up, the driver would need to conclude:

If I have low accident rates -->I drive minivans/larger sedans

But instead he restates in his conclusion what his friends said, which incorrectly infers cause from correlation:

If I drive a minivan/larger sedans --> I’ll have lower accident rates

#help

Could it help you to first identify the type of argument the stimulus is making before trying to weaken/strengthen?

The way I learned it is to categorize arguments as causal arguments vs everything else.

For causal arguments, which are v common, the approach to weakening is formulaic and in my experience almost always helps get to the right answer. You look for an answer choice that shows:

cause without effect;

effect without cause;

an alternate cause;

reversal of the cause and effect (less common).

When the argument is not causal, then you look for problems w the link between the premises and the conclusion. There will invariably be a gap (or an assumption) that was made and isn't fully bridged by the argument. So whatever the premises are don't justify the conclusion. Your job is to exploit that gap and pick an answer choice that either makes it bigger or shows why it's a problem.