Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_15187735_20 (episode INTEGER, segment_d VARCHAR)
### Question:
Which episode has segment D on custom motorcycle tanks?
### Answer:
SELECT MIN(episode) FROM table_15187735_20 WHERE segment_d = "Custom Motorcycle Tanks"