Choose appropriate option to complete the following sentence:

Vikram wrote _________ letter to his university yesterday but he forgot to post it.

a

The correct option to complete the sentence is a letter.

Here's why:

• "A letter" is the most appropriate indefinite article because Vikram wrote one specific letter.
• "Many letters" suggests he wrote more than one, which is not the case based on the sentence.
• "The letter" implies a definite letter, meaning a specific one that has already been mentioned or is assumed to be known to the reader. However, the sentence doesn't provide any context about a specific letter.
• "An" is not appropriate because "letter" is a noun that starts with a consonant sound, not a vowel sound.