https://github.com/ruby-association/prep-test/blob/dccfa77b6d3e409b7d818f4396fecf194f4b5839/silver.md?plain=1#LL767C1-L779C22
There seems to be a discrepancy between the question's prompt in silver.md and the provided answer in silver_answers.md.
Question 39 asks for two methods that can be used to obtain the desired output from the given Ruby code. However, only one correct method (d) delete_prefix is listed in the answers. In the current state, the question may lead to confusion. I recommend updating the question to reflect that only one method is the correct answer or review the available options and answers.