You will be given a definition of a task first, then some input of the task.
In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.

Passage: The Investigator was Gerry Anderson's first puppet production since The Secret Service (1969), the last Supermarionation series to be made by his former company Century 21 Productions. Having gone on to make the live-action series UFO and The Protectors, neither of which were made specifically for children, Anderson wanted to create something new for the younger audience and devised The Investigator as the template for a new Supermarionation programme, intending to pitch it to American network NBC in the hope that it would commission a series. The pilot was planned by Anderson, his wife Sylvia and their long-time business partner Reg Hill. Written by Sylvia from a story by Shane Rimmer, it was funded by private venture capital and produced by off-the-shelf company Starkits between The Protectors and a planned second series of UFO (which was later made as ).
Link Information: Gerry Anderson (born Gerald Alexander Abrahams; 14 April 1929 Answer: 40
Output:
At what age did Gerry Anderson produce The Secret Service?