Kevin 4

Let's start by defining some variables. Let:

K be Kevin's current age.
M be Margaret's current age.
From the problem, we know that Kevin is 4 years older than Margaret, so we can write:

K = M + 4

We also know that next year Kevin will be 2 times as old as Margaret, so we can write:

K + 1 = 2(M + 1)

Simplifying this equation, we get:

K + 1 = 2M + 2

Substituting K = M + 4 from the first equation, we get:

M + 4 + 1 = 2M + 2

Simplifying this equation, we get:

M + 5 = 2M + 2

Subtracting M from both sides, we get:

5 = M + 2

Subtracting 2 from both sides, we get:

M = 3

Substituting M = 3 into the equation K = M + 4, we get:

K = 3 + 4 = 7

Therefore, Kevin is 7 years old.

To verify this solution, we can check that it satisfies the conditions of the problem. Kevin is 4 years older than Margaret, so we have K = M + 4, which gives K = 3 + 4 = 7. Next year, Kevin will be 8 years old, and Margaret will be 4 years old. This is indeed 2 times Margaret's age, as required by the problem. Therefore, the correct answer is that Kevin is 7 years old.