Correct option is A
Option (a) contains the error.
Explanation of the error:
· The verb tense "has said" is in the present perfect, which is used to indicate an action that has relevance to the present moment or is unfinished.
· However, the sentence clearly refers to a specific action completed in the past, which makes simple past tense ("he said") more appropriate than present perfect ("has said").
· Also, "yet it" is correct here as a conjunction showing contrast between what he said and the effect of that speech (i.e., putting him in a bad light).
Corrected Sentence:
"I don't know the reason why he said all this, yet it puts him in a bad light."
Grammatical rule used:
· Use the simple past tense for actions that are completed and not connected to the present.
· The present perfect is generally used when the action has occurred recently or has an impact on the present time.
�� Example of correct usage of simple past:
· "He said something strange yesterday."
· �� Example of correct usage of present perfect:
· "He has said strange things before." (relevant to present)