Fill in the blanks in the given sentences in List-I with the appropriate prepositional phrases in List-II:

List-I	List-II
(Sentences)	(Preposition phrases)
(A) I drive to work, but I'd never do it ______ if I could avoid it.	(I) at once
(B) You should take the dessert out of the freezer and serve it ______.	(II) by choice
(C) I thought I understood the equation but ______ I realized it was complicated.	(III) at the very least
(D) The store should give me my money back or ______ offer to exchange the shoes.	(IV) on reflection

Choose the correct answer from the options given below:

Option 1 -> (A)-(IV), (B)-(II), (C)-(III), (D)-(I): "on reflection" doesn't fit with avoiding driving, and "by choice" doesn't work for serving dessert.

Option 2 -> (A)-(I), (B)-(II), (C)-(III), (D)-(IV): "at once" doesn't suit the context of avoiding driving, and the other matches are incorrect.

Option 3 -> (A)-(II), (B)-(I), (C)-(IV), (D)-(III): "by choice" fits avoiding something voluntary, "at once" means immediately for serving, "on reflection" means after reconsideration, "at the very least" indicates minimum expectation.

Option 4 -> (A)-(III), (B)-(IV), (C)-(I), (D)-(II): "at the very least" doesn't fit the driving context, and other combinations are semantically incorrect.

Hence, Option 3 -> (A) uses "by choice" to indicate the person drives out of necessity not preference; (B) uses "at once" meaning serve immediately; (C) uses "on reflection" meaning after thinking more carefully; (D) uses "at the very least" as a minimum acceptable alternative -> correct