Answer:
<u><em>A. wavelength</em></u>
Explanation:
The others are about sound and how high it is. That has nothing to do with time.
In a series circuit the total current is the same throughout resistors and so:

The voltage is distributed throughout the resistors and so:

and the total resistance can be calculated by adding up the resistors resistance:

First thing is to calculate the total resistance and so:

And by Omh's law V=IR we have:

And so the total current of the circuit is 1.2 amps i.e. 1.2 A.
C.) <span>The total mass of an object can be assumed to be focused at one point, which is called its center of "Mass"
Hope this helps!</span>
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