In a country, 60% of the male citizen and 70% of the female citizen ar

"60% of the male citizen are eligible to vote and 70% of those eligible, voted" - So 70% of 60% = 42% of total males voted

"70% of the female citizen are eligible to vote and 60% of those eligible, voted" - So 60% of 70% = 42% of total females voted

It doesn't matter how many of the total are males and how many are females. Since 42% of both voted, 42% of the citizens voted.

Answer (A)

Note that had we obtained different values for "% of total males who voted" and "% of total females who voted", we would not have been able to say the % of total citizens who voted. It would depend on what percentage of the total citizens are male/female.

To take a simple case, say
40% of total males voted
50% of total females voted

If the population has all males, 40% of the citizens voted.
If the population has all females, 50% of the citizens voted.
Depending on the proportion of males/females in the population, the percentage of citizens who voted changes.