Add the expressions 4 minus two-thirds b + one-fourth a and One-half a + one-sixth b minus 7. What is the simplified sum?

Negative one-sixth a + StartFraction 5 over 12 EndFraction b minus 3

Three-fourths a minus one-half b minus 3

Three-fourths a + StartFraction 5 over 6 EndFraction b minus 3

StartFraction 5 over 12 EndFraction a minus StartFraction 1 over 6 EndFraction b minus 3