Detailed Instructions: In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Problem:Context: before being appointed to command XXXXIX Mountain Corps. During his command of this corps it was involved in the invasion of Yugoslavia and the attack on the Soviet Union. Link Information: The invasion of Yugoslavia, also known as the April War or Operation 25, was a German-led attack on the Kingdom of Yugoslavia by the Axis powers which began on 6 April 1941 Question: Which of the two offensives that Kubler's Mountain Corps was involved in began first?
Solution:
Answer: invasion of Yugoslavia