Explanation:

There are four ways to place a group of four consecutive girls in a row of seven.

The girls can be permuted in each case 4!4!, and so can the boys (3!)(3!).

4×4!×3!=5764×4!×3!=576

If the intention of the author was that girls must sit next to a girl, and boys next to a boy, then there are only two ways to place the group of girls: GGGGBBB, BBBGGGG.

In that case, we have 2×4!×3!=2882×4!×3!=288.

Hence, option 4 is the correct answer.