Select the sentence in which articles have been used appropriately:-

A. There is a policeman at the door.
B. Some children suffer from a fear of the dark.
C. He has the good knowledge of English.
D. Tea we got on the bus, was cold.
E. He sent for a umbrella.

Choose the most appropriate answer from the options given below:

A and B only

The correct answer is Option (3) - A and B only

A. There is a policeman at the door. – Correct use of the article "a" for a singular noun.
B. Some children suffer from a fear of the dark. – Correct use of the article "a" with "fear."
C. He has the good knowledge of English.– Incorrect; it should be "good knowledge of English" without "the."
D. Tea we got on the bus was cold. – Incorrect; it should be "The tea we got on the bus was cold."
E. He sent for a umbrella. – Incorrect; it should be "an umbrella" because "umbrella" starts with a vowel sound.

Thus, **A and B** are the only sentences with appropriate article usage.