Regulatory affairs or clinical research or medical writing?

Hi

I complted MPharm Pharmacology and had experience as scientific analyst for 1 yr. As i felt there would no career growth in drug indexing field i'm in search of an another job close to my academics and more into pharma. My queries are:

1. Among regulatory affairs, clinical research and medical writing which would be better?

2.Do i need to pursue any course that would improve my oppurtunities?

3.How would be the CTC in the above options?

Please help me in choosing a good career option.