The company cannot build  10 child bikes and 12 adult bikes No, because the bike order does not meet the restrictions of 4c + 6a ≤ 120 and 4c + 4a ≤ 100 , Option A is the correct answer.
<h3>What is System of Inequality ?</h3>
System of inequality represent system of inequalities that satisfies common condition.
It is given that 
Each child bike requires 4 hours to build and 4 hours to test.
Each adult bike requires 6 hours to build and 4 hours to test.
Total building hours = 120
Total testing hours = 100
If c represents child bikes and a represents adult bikes, can the company build 10 child bikes and 12 adult bikes in a week. 
6a + 4c ≤ 120
4a +4c ≤100
On solving this system of Inequality
a ≤ 10 
which is less than required , and so
 No, because the bike order does not meet the restrictions of 4c + 6a ≤ 120 and 4c + 4a ≤ 100 
Therefore Option A is the correct answer.
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