Answer : 4. "pilfering"
Explanation :

“Embezzling” means misappropriating/stealing of funds placed in one’s trust or belonging to one’s employer. Hence, it does not fit the context properly.

The word ‘frauding’ is incorrect. “Fraud” is a noun; ‘-ing’ cannot be added to it. Hence, it can also be eliminated.

“Swindling” means ‘use deception to deprive (someone) of money or possessions’. It also does not fit the context properly.

“Looting” means ‘steal goods from (a place), typically during a war or riot”. It also does not fit the context aptly.

“Pilfering” means ‘stealing things of little value’.

As, ‘a bottle of oil’ can be considered a thing of not much value, ‘pilfering’ fits the blank appropriately.