Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Which best 10-year period has a best 2-year period of petrosian?

### Inputs:
table_name: table, columns: ['Position', 'best year', 'best 2-year period', 'best 3-year period', 'best 5-year period', 'best 10-year period', 'best 15-year period']

### Response:
SELECT best 10-year period FROM table WHERE best 2-year period = petrosian