Find the correct expression based on the formula Formula = (a3+63+c) / Va? x (b2 +c) a. (a*a) * (b*b + c*c)/(a*a*a+ b*b*b+ c*c*c) b. Math.Sqrt( a*a) * (b*b + c*c)/(a*a*a+ b*b*b+ c*c*c) O c. (a*a*a+ b*b*b+ c*c*c) / Math.Sqrt( a*a) * (b*b + c*c) O d. (a2*a +b2 *b+c2 *C)/(a*a) * (b*b + c*c) Nested Class is defined as O a. Writing a class within another is allowed in java O b. Class and its attributes c. Method containing another method O d. Class and its methods