Final answer:
The Martinez family used 1,600 kilowatts of electricity last April.
Step-by-step explanation:
The correct answer is option 1) kilowatts. The Martinez family used 1,600 kilowatts of electricity last April. Kilowatts is the appropriate unit of measure for electricity consumption. The other options - watts, volts, and amps - are not relevant for measuring the amount of electricity used.