The area of a trapezium is \[28\text{ }c{{m}^{2}}\]and one of its parallel sides is\[6\text{ }cm\]. If its altitude is \[4\text{ }cm,\] find its other parallel side.

• A. \[4\text{ }cm\]
• B. \[\text{8 }cm\]
• C. \[\text{6 }cm\]
• D. \[\text{10 }cm\]