\\(\n\\textbf{Definition:}\\ \\text{An informal gathering occurs when a group of people get together in a casual, relaxed manner.}\n\\)
\n\n\\(\n\\text{Evaluate the options:}\n\\)
\n\n\\(\n\\begin{aligned}\n\\text{A.}&\\ \\text{Book club meets on the first Thursday of every month} \n\\quad\\text{(regular, scheduled meeting — somewhat formal)}\\\\\n\\text{B.}&\\ \\text{Whenever she eats at the Italian restaurant, Kamalika seems to run into Peter} \n\\quad\\text{(chance encounter, not a group gathering)}\\\\\n\\text{C.}&\\ \\text{After his promotion, Jeremy and a few coworkers go out for a quick drink after work} \n\\quad\\text{(spontaneous, casual group — fits the definition)}\\\\\n\\text{D.}&\\ \\text{Mary sends out 25 invitations for a bridal shower} \n\\quad\\text{(planned, formal event)}\n\\end{aligned}\n\\)
\n\n\\(\n\\boxed{\\text{Correct choice: C}}\n\\)
\n