Final answer:
President Reagan believed that removing the Berlin Wall would result in improved relations between East and West Germany, contributing to the decline of Communist influence and Cold War tensions.
Step-by-step explanation:
According to President Reagan, one effect of removing the Berlin Wall would be c) Improved relations between East and West Germany. Reagan's 1987 speech at the Brandenburg Gate called on Gorbachev to "tear down this wall," signaling a desire for the end of the division between East and West Berlin. While Reagan did not predict the fall of the wall himself, the eventual dismantling in November 1989 symbolized the decline of Communism in Eastern Europe and sparked improved relations not only between the Germanys but also contributed to the broader decline of the Cold War.