Which one of the following is used in preparing a natural mosquito repellent?

The Lemongrass plant is known to be an excellent mosquito repellant.

According to a study conducted in 2011, around 95% of mosquitos from a specific range of species were either killed or completely repelled due to the intense odour of lemongrass oil.

Commonly known as Citronella oil, the impact of the essential oil from Lemongrass is known to last for around two and a half hours. For some species of mosquitos, it is even more.