Answer should be $A$.
As given in question
The contribution of each factor to the overall service quality is directly proportional to the factor score and its standardized coefficient.
So, $\text{contribution} \propto \text{factor score}\times \text{standardized coefficient}$
1. Contribution of outcome factor $= Q\times \text{factor score}\times \text{standardized coefficient}= Q\times 6\times 0.8$
$= 4.8 Q = 4.8$ $($Here, $Q$ the proportional constant assumed to be $1\ldots)$
Similarly,
2. Contribution of tangibles $= 5\times 0.4 =2$
3. Contribution of reliability $= 6\times 0.7= 4.2$
4. Contribution of responsiveness $=6\times 0.6= 3.6$
5. Contribution of empathy $= 4\times 0.6= 2.4$
6. Contribution of assurance $= 6\times 0.5= 3$
So, we can see here lowest contribution is "$2$" and total contribution is "$4.8+2+4.2+3.6+2.4+3= 20$"
The lowest contribution among all the above factors to the overall quality of services delivered by the company $=\left(\dfrac {2}{20}\right)\times 100= 10 \%$
