at or on, or else

[ggomad]

Kindly review the following question I struck upon in my studybook.

All applicants need go through medical exams ____ the instruction of the HR department, or else they will not be considered for any position.

A) to B) on C) for D) at

I thought both B and D could be correct. My studybook says the answer is D without decent explanation. It's kind of confusing.
What would you advise me?

In which similar context can "on" be used, and what differences should I take notice to distinguish these two difficult prepositions in the above sentence or any other similar ones?

 

[Casiopea]

Kindly review the following question I struck upon in my studybook.

All applicants need (to) go through medical exams ____ the instruction of the HR department, or else they will not be considered for any position.

A) to B) on C) for D) at

I thought both B and D could be correct. My studybook says the answer is D without decent explanation. It's kind of confusing.
What would you advise me?

In that context, at means, with reference to; as per, in accordance with. On in that context refers to, based on.

In which similar context can "on" be used, and what differences should I take notice to distinguish these two difficult prepositions in the above sentence or any other similar ones?

Good question! It's often not that easy to tell. Mind you, as per (the) instruction is a common phrase.

All the best,

 

[ggomad]

Thanks for clearing things up!
You really help me sleep light-hearted.^^

 

[Casiopea]

Thanks for clearing things up!
You really help me sleep light-hearted.^^

Honestly? :shock: That's fabulous! You're welcome.

 

[yulia]

These prepositions is indeed a difficult thing. I mean that most of the times when you think that you were right, you prove to be wrong. I know that it's all a matter of time, but still...