Given the integral: $\backslash$int $(28)/($x$^(2)\backslash$sqrt$($x$^(2)+49))$dx

A$.$ Which trig substitution should be used for this integral?

x$=49$tan$(\backslash$theta $)$

x$=7$sin$(\backslash$theta $)$

x$=49$sin$(\backslash$theta $)$

x$=49$sec$(\backslash$theta $)$

x$=28$sec$(\backslash$theta $)$

x$=7$tan$(\backslash$theta $)$

B$.$ What is your simplified new integral after all substitutions are made?

$\backslash$int

C$.$ Integrate, but leave in terms of $\backslash$theta $.$

D$.$ Lastly, what is the value of the original integral in terms of x $?$