Choose the opposite of the given word-
Base
a)Noble
b)Happy
c)Courageous
d)Carefully

Hint: Base refers to a person who is considered to be immoral or dishonorable. A basic person lacks moral principles and manners.

Complete answer:
An antonym or opposite is contrary in meaning to another word. Example- Superior is an antonym of inferior.
The word ‘base’ has been derived from the Medieval Latin word- Bassus, which means short.
We know the meaning and the origin of the word ‘base’. Now, let’s look at its usage:
Example- My neighbor is considered to be immoral and baser as she works late at night. Here, we can understand that X’s neighbor ‘Y’ is considered to be dishonorable or ignoble because she works late at night.
Let’s decipher the meaning of the given options-
Option a- ‘Noble’ refers to a person who is honorable and holds great moral values and principles. Example- The noblemen attended our ball last night. ‘Noble’ is the opposite in meaning to base. Hence, it is the correct option.
Option b- ‘Happy’ refers to the quality of being cheerful or delighted by something or someone. Example- She was really happy to see me. ‘Happy’ is different in meaning to base. Hence, it is an incorrect option.
Option c- ‘Courageous’ refers to the quality of being bold and brave. Example- The courageous knight saved the villagers. ‘Courageous’ is different in meaning to base. Hence, it is an incorrect option.
Option d- ‘Carefully’ refers to perform an action cautiously to avoid any harm. Example- I carefully peeled the chili. ‘Carefully’ is different in meaning to base. Hence, it is an incorrect option.
The correct answer is Option ‘a’.

Note: The word ‘base’ was originally used to refer to a low or inferior quality item or person. We started using ‘base’ to indicate people of the lower social strata. ‘Base’ has several meanings; hence we need to look at the options beforehand.