The decimal floating point number $-40.1$ represented using IEEE-754 $32$-bit representation and written in hexadecimal form is:

Given number is

$-40.1$

Since the number is negative, sign bit is

$1$

Now,

$40.1$ in binary is approximately

$101000.000110011001100110\ldots$

Normalize it:

$101000.000110011001100110\ldots=1.01000000110011001100110\ldots\times 2^5$

So, exponent is

$5$

IEEE-754 single precision bias is

$127$

Biased exponent is

$127+5=132$

Binary of $132$ is

$10000100$

Mantissa bits are

$01000000110011001100110$

So, IEEE-754 representation is

$1\ 10000100\ 01000000110011001100110$

This gives hexadecimal form:

$\text{C2206666}$

Therefore, the answer is

$\text{0xC2206666}$

Hence, the correct answer is Option 1.