Step-by-step Solution:

The formula for Effective Memory Access Time (EMAT) is: \[ \text{EMAT} = \text{(Hit Ratio)} \times \text{Cache Access Time} + \text{(Miss Ratio)} \times \text{(Cache Access Time + Memory Access Time)} \]
Here:
Hit Ratio = \( 1 - \text{Miss Ratio} \) = \( 1 - 0.15 = 0.85 \)
Cache Access Time is negligible compared to memory access time, so we consider it approximately \( 0 \).
Miss Ratio = \( 0.15 \)
Memory Access Time = \( 10 \, \text{ms} \)

Substitute values: \[ \text{EMAT} = (0.85) \times (0) + (0.15) \times (10 \, \text{ms}) \] \[ \text{EMAT} = 0 + 1.5 \, \text{ms} \] Final Answer:
B. 1.5 milliseconds