Is this a connexus question? because if it is the answer would be c
The correct option is B. The rule is when one of the nouns connected by 'or' or 'nor' is plural then the verb must be plural and the plural subject should be placed next to the verb. Here, 'Surendra' is singular subject and 'his friends' is plural subject thus 'have been' is used which is plural verb. Hence, 'Have been' is the best fit according to the rule
Draw an wavelength it creates equal rhythm throughout
1.
an abstract or general idea or term.