Bad custom is the obstacle of the social development justify the statement

Social problems are the issues that are collectively faced by a society. It is not only related to one individual but a whole society. For example; illiteracy, poverty, infanticide, child abuse, child labour etc.  

Social evils are those activities that negatively affect a country. For example; alcoholism, drug abuse, prostitution etc.  

Both social problems and evils badly affect a country. They are a hurdle in the development of the country.  

(i) Solving these issues and evils consumes time, hence development is ignored.  

(ii) Plans and projects of eradication of evils and problems are to be made; hence development plans are ignored.  

(iii) Youth is the leading force of a country but they become a target of these

(iv) The international image of the country is negatively affected; hence there is lack of resources and trading opportunities.

(v) There is unrest within the country

Explanation:

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."