Explanation:

- In 1964, many global businesses were eyeing expansion into different markets, but this year isn't linked to IBM and Coca Cola's exit from India.

- By 1981, various industries worldwide were witnessing transformations, but this year doesn't correspond with the specific event you mentioned.

- 1956 was a time of post-war economic adjustments globally, yet it isn't relevant to the issue of IBM and Coca Cola's operations in India.

- 1977 is when IBM and Coca Cola decided to leave India due to the Foreign Exchange Regulation Act. This act limited foreign ownership to 40% in Indian enterprises, leading these companies to exit the market rather than comply with this restriction.