Which of the following phrases (I), (II), and (III) given below each sentence should replace the phrase printed in bold letters to make the sentence grammatically correct? Choose the best option among the five given alternatives that reflect the correct use of phrase in the context of the grammatically correct sentence. If the sentence is correct as it is, mark (e) i.e., “No correction required” as the answer. 

Q:

Revolutionary scientists designed varieties of strategies to make the will of the people discernible.
I. a multiple strategies
II. several strategies
III. multitude of strategy

• 1
  Only I is correct
• 2
  Only II is correct
• 3
  Only III is correct
• 4
  Both I and III are correct
• 5
  No correction required