Explanation
$$\textbf{Step 1:Write the}$$ $$\boldsymbol{{r^{th}}}$$ $$\textbf{term of the binomial expansion}$$
Since, $${r^{th}}$$ term of the expression $${\left( {a + b} \right)^n}$$ is $${T_{r + 1}} = {}^n{C_r}{\left( a \right)^{n - r}}{\left( b \right)^r}$$
Therefore, $${r^{th}}$$ term of the expression$${\left( {\sqrt 2 + \sqrt[4]{3}} \right)^{100}}$$is $${T_{r + 1}} = {}^{100}{C_r}{\left( 2 \right)^{\frac{{100 - r}}{2}}}{\left( 3 \right)^{\frac{r}{4}}}$$
$$\textbf{Step 2 : Apply the condition of a number to be a rational number}$$
$${r^{th}}$$term of the expression is a rational term if
$$\frac{{100 - r}}{2}$$ and $$\frac{r}{4}$$ should be integer
Therefore, $$r$$ should be multiple of 4 $$ \Rightarrow r = 0,4,8,12.............100$$
Which forms an A.P. with first term$$(a) = 0;$$common difference$$(d) = 4;$$
$${n^{th}}$$term$$({A_n}) = 100$$
since, $$A_{n}=a+(n-1)d$$
$$ \Rightarrow 100 = 0 + (n - 1)4$$
$$ \Rightarrow n = 26$$
$$\textbf{Hence, Option ‘B’ is correct.}$$
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