Fill in the blank with the appropriate word from the options given be…

The correct answer is Option (1) → hence

Linking word of result:

• Hence means for this reason, therefore; it introduces a result of what has just been said.
• Linking words show the relation between two ideas: result (hence, therefore), contrast (however, nevertheless, but).
• Deciding clue: he is a perfectionist, and as a result he is seldom satisfied with average work, so a word of result is needed.
• Complete sentence: The director is a perfectionist, hence, he is seldom satisfied with average performance.
  Example: He did not prepare well; hence, he failed.

Why the Other Options are Incorrect?

Option 2: however — Incorrect. However shows contrast; being seldom satisfied follows from being a perfectionist, it does not go against it.
Example: The task was hard; however, she finished it on time.

Option 3: nevertheless — Incorrect. Nevertheless means in spite of that and introduces something unexpected; here the second idea is expected.
Example: It was raining; nevertheless, they went out.

Option 4: but — Incorrect. But joins two contrasting ideas; there is no contrast between the two clauses.
Example: He is clever, but he is lazy.