The E-100 pilot project, launched in Pune in June 2021, is related to the production and distribution of ethanol. Ethanol is a type of biofuel that is produced from various sources such as sugarcane, corn, and wheat. It is used as an alternative fuel for vehicles, and it is considered a cleaner and more sustainable option compared to conventional gasoline.

Option 1: COVID-19 vaccine - This option is incorrect as the E-100 pilot project is not related to the production and distribution of COVID-19 vaccines. COVID-19 vaccines are developed and produced by pharmaceutical companies and are unrelated to the production of ethanol.

Option 3: Electric vehicle - This option is incorrect as the E-100 pilot project is not related to electric vehicles. Electric vehicles use electricity as their primary source of power, whereas ethanol is used as a fuel for internal combustion engines.

Option 4: Ethane - This option is incorrect as the E-100 pilot project is not related to the production and distribution of ethane. Ethane is a hydrocarbon that is primarily used as a feedstock for the production of ethylene, a chemical used in the manufacturing of various products such as plastics.

In conclusion, the correct answer is option 2: Ethanol.