Step 1: Understanding the Concept:
"Moribund" means at the point of death, inactive, or declining.
Step 2: Detailed Explanation:
The opposite of moribund would be active, growing, or flourishing.
(A) Declining - similar meaning (synonym)
(B) Waning - similar meaning (synonym)
(C) Thriving - growing vigorously, flourishing (antonym)
(D) Pessimistic - a mental attitude, not directly opposite
(E) Glorifying - praising, unrelated
Step 3: Final Answer:
Thriving