Answer: B) 25%
The min is 4 as this is the smallest value and it is visually shown as the left-most point on the boxplot. This is the tip of the left whisker.
The value of the first quartile (Q1) is the left edge of the box and that is 7. The left whisker goes from 4 to 7. The left whisker represents 25% of the data, which is another way of saying "25% of the data is below Q1". So 25% of the distribution has between 4 and 7 teams.