Select the correct option: The biochemist insisted ___ conducting a double-blind trial before publication.

Correct — B. The trigger is the verb insisted followed by an -ing form, conducting.

Insist takes the fixed preposition on (formally, upon) before a noun or gerund: 'insist on accuracy', 'insist on doing it yourself'.

So the sentence reads 'The biochemist insisted on conducting a double-blind trial before publication' → option (b).

Why the others are wrong

• (a)
  with — With is not the preposition insist takes before the thing demanded. 'Insisted with conducting' is not idiomatic. The demand is marked by on, as in 'insist on silence'.
• (c)
  to — To tempts because verbs like want and refuse take to + infinitive. Insist does not: 'insisted to conduct' and 'insisted to conducting' are both errors.
• (d)
  about — About follows verbs of talking or worrying, such as talk about and worry about. Insist is a verb of demanding, and its preposition is on.

Many English verbs lock in a dependent preposition, chosen by the verb rather than by the meaning of the sentence: insist on, depend on, persist in, object to, abstain from.

Whatever follows that preposition is a noun or an -ing form. Here the -ing form is conducting, so the blank must hold the preposition insist takes.

Insist has a second pattern, a that-clause: 'She insisted that the trial be conducted.' In standard English it is not followed by to + infinitive.

Key facts

• Insist takes on or upon before a noun or -ing form: insist on doing.
• Insist can also take a that-clause with should or the base form: she insisted that he (should) leave.
• After a preposition a verb takes the -ing form: on conducting, not on conduct.
• Other verbs that take on: depend on, rely on, focus on, dwell on.

Common traps

• Writing insist to + infinitive by analogy with want to or refuse to
• Choosing about because insisting feels like talking about something

No directly related past PYQ was found.