Question

the antonym of simple is - difficult/complicated/easy/tricky.
choose between one​

Answer 1

The antonym of simple is "difficult"

Other words may be it's antonym but difficult is most appropriate.

Antonym is the word which have the opposite meaning of the given word.

For example, if we are asked to give antonym of day then it will be night because they are just opposite to each other.

Answer 2

Explanation:

the antonym of simple is - difficult