Select the most appropriate option to fill in the blank.
The secretarial job,___________, was advertised on the internet.

Option A: "for which she has applied"; this option correctly uses "for which" to refer back to the secretarial job. It indicates that she has applied for the job. The preposition "for" is necessary here to indicate the action of applying for something.

Option B:  "which she has read" The phrase "which she has read" suggests she simply read the advertisement but does not imply any further action.

Option C: "That she bought." this option is incorrect because it does not make sense in the context of a job advertisement. You cannot buy a job. 

Option D: "for which she has written." this option could make sense in a different context, such as if she wrote the job advertisement herself. However, it does not fit the common scenario where someone applies for a job. The typical and expected action related to a job advertisement is applying, not writing the advertisement.

Overall, A would be a better fit over D

Therefore, Option A is the correct answer.