English grammar — parallel structure and tense: Choose the option that best improves the sentence. Original sentence: "He admired the speed with which he completed the work and appreciating the method adopted by him" Select the replacement for the underlined segment to make the coordination parallel.

Given data

• First verb: "admired" (past simple).
• Second coordinated element must match the tense and form.

Concept/Approach
Maintain parallelism in coordinated predicates: past simple + past simple. Also keep the natural collocation "appreciated the method adopted (by him)".

Option analysis
A. "appreciate … being adopted" → wrong tense and awkward passive progressive.B. "appreciated the method adopted" → correct tense and idiom. ✔C. "appreciate the method of adoption" → incorrect structure and tense.D. Redundant/incorrect phrasing.E. No correction → original mixes "admired" with "appreciating" (nonparallel).

Corrected sentence
"He admired the speed with which he completed the work and appreciated the method adopted by him."

Final Answer
appreciated the method adopted