Under the Ryotwari system of assessment, the British Government collected revenue directly from the farmers.

Zamindari: This option is incorrect. The Zamindari system involved intermediaries known as Zamindars who collected revenue from the farmers and paid it to the British Government. The revenue collection was not done directly by the British Government.

Annawari: This option is incorrect. The term "Annawari" is not a recognized system of assessment in the context of revenue collection in British India.

Desaiwari: This option is incorrect. The term "Desaiwari" is also not a recognized system of assessment in the context of revenue collection in British India.

In summary, the correct answer is option 2, Ryotwari, where the British Government collected revenue directly from the farmers.