Nisha's father was 38 years of age when she was born while her mother was 36 years old when her brother four years younger to her was born. The difference of ages of her parents is:

 The alphabets are coded as shown :

$$\begin{gathered} R O S ? E C H A I P \\ 6 8 2 1 7 3 4 5 9 \end{gathered}$$

So, in SEARCH,

S ia coded as 2,
E as 1,
A as 4,
R as 6,
C as 7,
H as 3.
Thus, the code for SEARCH is 214673

If each consecutive letter in "happiness" relates to the consecutive numbers in 517768399, then H=5, A=1, P=7, I=6, N=8, E=3 and S=9.

Using the numbers that relate to the letters in 'senipah', you will arrive at

SENIPAH = 9386715.

Hence, Happiness is to 517768399 as senipah is to 9386715.

 The alphabets in the given words are coded as follows :

$$\begin{gathered} M ? I ? S ? T ? A ? K ? E N D \\ 9 7 6 5 4 1 2 8 3 \end{gathered}$$

D is coded as 3,

I as 7,
S as 6,
T as 5,
A as 4  and
N as 8.
So, the code for DISTANT is 3765485.

Only option b will be apt among all the statements above

Floors   Persons

6.           D

5.           F

4.           B

3.           A

2.           C

1.           E