Clark and Florence Wallace, a husband-and-wife medical team, worked st

Hi Vivek,
Clark and Florence Wallace, a husband-and-wife medical team, worked steadily and efficiently through the night, but sipping their coffee the next morning, she noticed that he seemed disoriented.

Since the meaning of this sentence is simple to comprehend, let’s proceed to the error analysis:
1. The verb-ing modifier “sipping their coffee the next morning” suggests that she (Florence) was drinking her coffee as well as her husband’s coffee. This does not sound logical. Both the husband and their wife were sipping their own coffee. Hence, we have modifier issue here.

POE:
(A) sipping their coffee the next morning, she noticed that he seemed disoriented: Incorrect for the reason stated above.

(B) sipping their coffee the next morning, he seemed to be disoriented, she noticed: Incorrect.
1. This choice repeats the same modification error of choice A. Now it suggests that he (Clark) was drinking both their coffees.
2. Also two independent clauses are joined just by a comma. This leads to run-on sentence.

(C) as they sipped their coffee the next morning, she noticed that he seemed disoriented: Correct.

(D) as they were sipping their coffee the next morning, he seemed, she noticed, disoriented: Incorrect. Same run-on sentence error as in choice B.

(E) he seemed disoriented, she noticed, sipping their coffee the next morning: Incorrect.
1. This choice also repeats the run-on sentence error.
2. Verb-ing modifier “sipping…” is now modifying the preceding clause, suggesting that she (Florence) was drinking her coffee as well as her husband’s coffee.

Hope this helps.
Thanks.
Shraddha