The correct answer is D. will have passed.
The sentence “By the end of summer, you will have passed your higher secondary examination” is in the future perfect tense. The future perfect tense is used to talk about actions that will be completed by a specific time in the future. In this case, the action is “passing your higher secondary examination” and the specific time is “the end of summer.”
The other options are not correct because they do not express the idea that the action will be completed by a specific time in the future. Option A, “will pass,” is in the simple future tense. The simple future tense is used to talk about actions that will happen in the future. However, it does not specify when the action will happen. Option B, “will be passed,” is in the passive voice. The passive voice is used to focus on the action rather than the person or thing doing the action. In this case, the passive voice would suggest that someone else will pass you on your higher secondary examination. Option C, “will be passing,” is in the progressive tense. The progressive tense is used to talk about actions that are happening or will be happening at a specific time in the future. However, it does not specify when the action will start or end.