human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: D 41 O, D 42 O, D 43 O, D 44 O, D 45 +, R 55 +, R 54 +, R 53 +, R 52 O, R 51 O
###Question: What is the value of D 42 O that has an R 53 + value of r 8?
gpt
SELECT D 42 O FROM table WHERE R 53 + = r 8