please give a detailed explanation, im genuinely trying in this class

Answer:
C) [tex]\frac{\sqrt{6} }{14}[/tex]
Step-by-step explanation:
We multiply the conjugate (7 √2) with the denominator and numerator:
[tex]\frac{\sqrt{3} }{7\sqrt{2} } *\frac{-7\sqrt{2}}{-7\sqrt{2}} \\\\\frac{\sqrt{6} }{14}[/tex]
I also just used my calculator and it gave me this