Correct option is B
Given:
1. Petrol 2. Petrify 3. Pet 4. Petal 5. Petition
Now, we check given terms.
Pet will be first
Petal (Pet + 'a' comes next)
Petition (Pet + 'i')
Petrify (Pet + 'r' comes after 'i')
Petrol (Pet + 'r' + 'o' — after Petrify alphabetically)
Dictionary order is:
1. Pet 2. Petal 3. Petition 4. Petrify 5. Petrol
Petition word will come at ‘Third' position.
Thus, correct option is (b).