Mark has a bag containing a mixture of 30 green and white marbles. Without looking, he guesses that half of the marbles in the bag are green. He randomly selected 1 marble from the bag, recorded the color, and returned the marble to the bag. After 15 trials, Mark has drawn 10 green marbles and 5 white marbles. Which of the conclusions below is BEST supported by his data?

The bag contains more white than green marbles.

The bag contains 10 green marbles and 20 white marbles.

The bag contains an equal amount of each color.

The bag contains more green than white marbles.