LR:

Always highlight premises yellow, conclusions pink. Context gets underlined.

RC:

Highlight author's voice in pink (anything that indicates their personal opinion), basic facts in yellow. Main point/conclusion gets orange.

I fell for the trap of answer D, but here's how I mapped the flawed reasoning to be sure of how A is correct.

Premise:

Inflammatory → Inappropriate (Riley's argument in first sentence)

Inflammatory (Author's characterization of Riley's argument)

Conclusion:

Inflammatory → Inappropriate (Group 3 translation of conclusion)

Author mistakes sufficiency for necessity

I thought JY was wrong about answer A not being appealing, but after his explanation it became obvious that no other answer other than C even meets the requirements to be selected. Very simple and well-done explanation!