The correct statement is option 2, which means that statements 1, 2, and 3 are correct.

Statement 1 is correct because the architecture of hill stations in colonial India was indeed designed to recreate the European style. The British wanted to create an environment that reminded them of their home country.

Statement 2 is correct because hill stations were developed as sanitariums, where soldiers and other British officials could seek treatment for illness. The cool climate and fresh air of the hill stations were believed to be beneficial for health.

Statement 3 is correct because Shimla, one of the most famous hill stations in colonial India, became the official residence of the Commander in Chief of the Indian Army. The British chose Shimla as their summer capital and it became an important administrative center.

Statement 4 is incorrect. There is no mention of Shimla being evacuated in 1864 due to a Typhoid epidemic.