Inferential stats

A student hypothesized that girls in his class had the same blood pressure levels as boys. The probability value for his null hypothesis was 0.15. So he concluded that the blood pressures of the girls were higher than boys’. Which kind of mistake did he make?
a) Type I error b) Type II error c) Type I and II errors d) Did not make an error
My reasoning: I'm thinking since it failed to reject the null hypothesis if it's false....it must be a Type II error. But i'm having trouble with this error. Any help would be much appreciated.