Fill in the blank with the appropriate modal : Till 1990, I ____ read…

The correct answer is Option (1) → (C) Only

Could is the past form of can and expresses ability in the past. "Till 1990" points to a past period, and the sentence speaks of the ability to read without glasses at that time: "Till 1990, I could read without glasses."

Complete sentence: Till 1990, I could read without glasses.

(A) should — Incorrect.

• Should expresses duty or advice, not ability.
  Example: You should wear glasses while reading.

(B) shall — Incorrect.

• Shall refers to the future, but "Till 1990" is in the past.

(C) could — Correct.

• It shows past ability.

(D) will — Incorrect.

• Will also refers to the future and does not fit a past period.

Tip: In this question the options do not follow the order of the statements (Option 1 = (C) Only, Option 2 = (B) Only, Option 3 = (A) Only, Option 4 = (D) Only). NTA often jumbles the options in this way, so after finding the correct statement, read the options carefully and mark the one with the right letter.