Utilize the input text as a context reference, choose the right relationship between David Johnston and University of Waterloo from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

David Johnston went with me to New Delhi to meet Kalam and came back so impressed by the late president that his University of Waterloo decided to honour Kalam."
employer