Many people like to have ______ with some ketchup.
(A) salad (B) French fries (C) pork (D) spaghetti
The answer is option B. What's wrong with the other options?
This is a cultural, not a language, question. You might eat pork with ketchup if it was particularly dry and tasteless, but French fries are the most common use of the condiment.
Spaghetti is commonly served in a tomato-based sauce, so there would be no need to add another tomato-based condiment.
And I've never heard of anyone using ketchup on salad, though I suppose it's possible. It's a little sweet for covering vegetables.