In the following question, a sentence is provided with one part highlighted in bold. The bold part may or may not contain an error. The options given below can replace the highlighted part. Choose the option that correctly replaces the erroneous phrase. If the sentence requires no change, select 'No replacement required' as your answer.

Do not let your failures to shake your resolve.

The correct option is shake your.

Explanation:
In English grammar, the verb "let" functions as a causative verb. When "let" is followed by an object, it requires a bare infinitive (the base form of the verb without the word "to") rather than a full infinitive (a verb preceded by "to").

Grammatical Structure:
Subject + let + object + bare infinitive (base verb)

In the given sentence:
• Incorrect: "Do not let your failures to shake your resolve." (Uses full infinitive "to shake")
• Correct: "Do not let your failures shake your resolve." (Uses bare infinitive "shake")

Therefore, the bold part "to shake your" should be replaced with "shake your" to make the sentence grammatically accurate.