What is the relationship between solute amount and molarity (direct or indirect)

I think molarity and amount of solute are directly related since if you increase the amount of solute in a given volume the molarity increases as a direct result.  M=(mol of solute)/(L of solution)
I hope this helps.  Let me know in the comments if anything unclear.

The most plausible answer is b, duration. the given amount of time is considered how long it last for.