Select the most appropriate option to substitute the underlined segment in the given sentence. If there is no need to substitute it, select ‘No substitution required’.
With who did you discuss the intricate details of the project, seeking input from various experts, each of whom offered valuable insights, culminating in a meticulously crafted plan that garnered unanimous approval from the team?
1
For who
2
At whose
3
With whom
4
No substitution