Though he worked very hard . . . . . . . . he could not get the highest marks. A. in spite B. also C. but D. yet

The correct answer is: but.

The word “but” is used to introduce a contrast or contradiction. In this case, the speaker is saying that although the person worked very hard, they were not able to get the highest marks.

The other options are not as appropriate in this context.

• The word “in spite” can be used to introduce a clause that gives a reason for something. However, in this case, the speaker is not giving a reason for why the person did not get the highest marks. They are simply stating that they did not get the highest marks, even though they worked very hard.
• The word “also” can be used to introduce a clause that adds information to something. However, in this case, the speaker is not adding any information. They are simply stating that the person worked very hard and did not get the highest marks.
• The word “yet” can be used to introduce a clause that expresses a contrast or contradiction. However, in this case, the speaker is not expressing a contrast or contradiction. They are simply stating that the person worked very hard and did not get the highest marks.