The most important aspects in writing a research proposal are $($i$)$ the project outline of the research proposal $($ii$)$ the purpose of writing a research proposal $($iii$)$ the style of the research proposal $($iv$)$ the format of the research proposal $($v$)$ the literature reviewed in the research proposal.

a$.$

Number ii iii and iv

b$.$

Number i iii and v

c$.$

Number ii iv and v

d$.$

Number i ii and iii