ব্যাখ্যা
Correct Answer: (B) is
Subject-verb agreement with collective measurements is a classic and frequently tested grammar point in NTRCA English.
The Core Rule — Collective Measurement as Subject:
When a sum, distance, amount, or quantity of money is used as the subject of a sentence, it is treated as a SINGLE UNIT and takes a SINGULAR verb — even if the number appears plural.
Application:
"Fifty miles is not a long distance."
— "Fifty miles" is treated as a single distance (one measurement unit), NOT as 50 separate miles.
— Therefore, it takes the singular verb "is."
More Examples of This Rule:
— "Ten dollars is all I have." ✓
— "Three hours is a long time to wait." ✓
— "Two kilometres is not far from here." ✓
— "Sixty percent of the work is done." ✓
Contrast — When Plural Verb is Used:
If the items are considered individually (not as a single unit):
— "The fifty miles were covered in stages." (each mile counted separately)
— But in most everyday contexts, measurements → singular verb.
Why others are wrong:
✗ "are" — plural verb; wrong because "fifty miles" is a singular collective measurement
✗ "have been" — present perfect; wrong tense and number
✗ "were" — past tense; the sentence is a general truth, not a past event
Source: English Grammar in Use — Raymond Murphy; NTRCA Question Bank.