Which two states of India are the leading producers of mineral oil?

Directions: In the question given below, a part of the sentence is highlighted. Below are given alternatives to the highlighted part at (A), (B) and (C) which may improve the sentence. Choose the correct alternative. In case no improvement is needed your answer is (D). 
Scarcely had he left when his friend came. 

Which of the following guarantees the purity of food items?

When is National Consumer Day celebrated in India?

When was the Human Rights Commission established?

Where is the headquarters of International Organization for Standardization (ISO)?

In which year the right to service was imposed in Bihar?

Directions: In the following question, some of the sentences have errors and some have none. Find out which part of a sentence has an error and mark your answer. If there is no error, mark our answer as (D).
Rajiv was unhappy to (A)/ hear the news of his (B)/ son's failing in the final examination. (C)/ No error (D)