Hi CJ!
Congrats on scheduling your exam, it's a great step in your professional development!
I would say the exam has 40% of the waterfall questions and around 60% with agile/hybrid approach. As my colleagues have already mentioned, the exam is based on the exam content outline which can be downloaded for free here: www.pmi.org/certifications/project-manag...pmp-exam-preparation

No, there are no options like that during the exam. As a candidate for the PMP certification, you are expected to be able to answer questions covering a range of approaches.
I strongly suggest you read the Exam Content Outline (ECO) document that you can download from PMI.org to get a clearer idea of the exam.
(Edit: Harry beat me to it. )

CJ:

I will confirm with 100% certainty that you do NOT have a choice on which approach you will be examined on. The exam is the exam and will be unique to you once you log in as it is generated at the time of login. Use the Exam Content Outline available from PMI in your preparation. I strongly recommend that you use an exam simulator in your preparation. The PrepCast has a very, very good one.

Harry

I'm prepping for the exams, have scheduled April. Can someone confirm if in the exams I have an option of chosing which approach (traditional waterfall, Agile or Hybrid) I will be examined on.