In the question given below, a sentence is given, divided into parts. One of the parts may contain an error. Identify the part that contains the error, and mark it as the answer. Ignore errors of punctuation. In case the sentence is correct as it is, mark option (e), that is, 'No error'. In August 2020, then President Trump had invoked his emergency economic powers to issue an executive order that imposed broad sanctions against TikTok on national security grounds.

In the sentence, "had invoked" is incorrect in this context. The past perfect tense ("had invoked") is unnecessary because the action of invoking occurred in the past and does not need to be placed earlier than another past action. The correct tense here would be the simple past tense ("invoked") to indicate a past action in a specific timeframe. The corrected sentence would be: "In August 2020, then President Trump invoked his emergency economic powers to issue an executive order that imposed broad sanctions against TikTok on national security grounds."