Concept:The correct phrase uses the intensifier pattern “much too” before an adjective to mean “excessively.”
Explanation:The sentence needs an adverb phrase that correctly modifies the adjective “difficult.”
The phrase “too difficult” means “more difficult than is acceptable.”
To add emphasis, we use “much” before “too,” giving the standard form “much too difficult.”
Option A, “much too difficult,” is grammatically correct and natural.
Option B, “too much difficult,” is wrong because “too much” modifies nouns, not adjectives.
Option C, “more too difficult,” is incorrect because “more” cannot combine with “too.”
Option D, “quit to difficult,” is a misspelling and ungrammatical; the correct form would be “quite too difficult,” which is not idiomatic here.
Therefore, only option A fits the sentence.
Answer:A. much too difficult
The task is much too difficult for us to undertake.