WAEC - English Language (1990 - No. 43)
From the words or groups of words lettered A to D, chose the word or group of words that best completes the sentence.
Mary said she was acting ... the instructions of the principal.
Mary said she was acting ... the instructions of the principal.
by
on
for
through
Erläuterung
So, the completed sentence is:
"Mary said she was acting on the instructions of the principal."
"Acting by" could suggest proximity or means.
"Acting for" could imply acting on behalf of someone.
Acting through" suggests a process or medium.
"On" is the correct preposition to use when referring to following or acting according to instructions. Therefore, B. on is the correct answer.