Select the most appropriate option that can substitute the highlighted segment in the given sentence. If there is no need to substitute it, select ‘No substitution.’
She is the eldest member of our town.

Correct option is D

The correct substitution of the highlighted words is is the oldest. The phrase "the eldest member" could be ambiguous between age and seniority.
"Is the oldest" more accurately specifies that she is the oldest in terms of age, which is the intended meaning here. Grammatical rule used: "Eldest" typically refers to rank or order among siblings, while "oldest" is used more broadly to refer to age in general contexts. Example: She is the oldest member of the group, with a decade more experience than the rest.