Bobby collects data from 30 adolescents (15 aged 13-15 and 15 aged 16-18) on the average minutes of daily practice on the guitar and converts the data to ranks. He wants to know whether age is related to practice time. He should compute a ______.
Group of answer choices
A. Mann-Whitney U test
B. Spearman's rho
C. Wilcoxon T test
D. Rank Sums test