If ⊗, O, ⊙ and • represent some integers on the number line, then the descending order of these numbers is

•, ⊗, ⊙, O
⊗, •, ⊙, O
O, ⊙, ⊗, •
O, •, ⊗, ⊙
Step 1: On a number line, a point to the right stands for a greater number. A point to the left stands for a smaller number.
Step 2: For descending order, we list numbers from the biggest to the smallest. So we read the marked points from right to left.
Step 3: From the picture, the order of the marks from right to left is: O, ⊙, ⊗, •.
Step 4: Write the comparisons one by one:
( O > , ⊙ )
( ⊙ > , ⊗ )
( ⊗ > , ullet )
Step 5: Therefore, the descending order is:
O, ⊙, ⊗, •
This matches option (c).