Solution:

As given in the hint, phonetics make it easier to comprehend spelling and enhances confidence. 
illustration- Hen, ten, den have the same vowel sounds. 
Now, let’s look at the given word- ineludible refers to commodity that is necessary or unpreventable. The word, ineludible has been derived from the Latin word- Inevitabilis, which means necessary. 
Let’s examine the given options 
a) ineludible- This word is spelled correctly. Hence, it's the correct option. 
b) Ineventable- This word is spelled erroneously. You can understand the difference in the phonetic sounds of ineludible and ineventable. Hence, it's an incorrect option. 
c) Inventable- This word is spelled erroneously. You can understand the difference in the phonetic sounds of ineludible and inventable. Hence, it's an incorrect option. 
d) Invitable- This word is spelled erroneously. You can understand the difference in the phonetic sounds of invitable and ineludible. Hence, it's an incorrect option. 
The correct answer is Option ‘ a ’.