Step 1: Understanding the Concept:
The sentence describes a consequence of banks not performing their role.
Step 2: Detailed Explanation:
"Lucrative" means profitable, fitting for government business. "Fail to fulfil" is a correct negative conditional. "Valuable" could work, but "compete" doesn't fit the conditional structure. "Neglected" is past tense, but the sentence requires a present tense verb after "if." "Succeed" would reverse the meaning. "Lucrative, fail" is correct.
Step 3: Final Answer:
lucrative, fail