Utilize the input text as a context reference, choose the right relationship between Theresa May and Home Secretary 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.

British Home Secretary Theresa May and French Interior Minister Bernard Cazeneuve visited the tunnel Thursday announced plans for a "substantial" increase of security guards, higher fences, surveillance cameras, floodlighting and infrared detection technology.

Answer: position_held