Explanation:

Pick up the unit digit of each number and multiply them;

3 in 853

2 in 452

6 in 226

6 in 1346

∴ 3 x 6 x 2 x 6 = 216 (consider the unit digit in the product)

So, the unit digit in the product of 853 * 1346 * 452 * 226 is 6.e 195.