Correct Answer: Deficient

Solution : The correct answer is option 4.

Explanation:

- The term "adequate" denotes an amount or quality that is satisfactory or acceptable.
- Let's examine the following alternatives' meanings:

• Requisite - Required for a specific function.
• Tolerable- decent, or mediocre.
• Ample - Sufficient or abundant in quantity.
• Deficient: Not having enough of anything; inadequate or insufficient.