Formal language is also called "proper language" because it is the type of language you would use when first meeting someone or giving a speech at a high class place so the correct answer is:
<span>B) Have I convinced you that the study of grammar is important and well worth your effort? </span>
Is there a poem if so can i please have the name of the poem so i can help you :)
Your answer for this question would be the second option because in a poem worldly possessions is where you control and mess up the language. Hope I helped (: