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

### Instruction:
Who is the builder for br no. 31779?

### Inputs:
table_name: table, columns: ['SECR No.', 'SR No.', 'BR No.', 'Builder', 'Date Delivered', 'Date Withdrawn']

### Response:
SELECT Builder FROM table WHERE BR No. = 31779