Final answer:
Albania is the nation that joined the Warsaw Pact in 1955 and NATO in 2009. It is alphabetically first among members of both these alliances.
Step-by-step explanation:
The correct answer to the question is A) Albania. Albania was a founding member of the Warsaw Pact in 1955, but later withdrew in 1968. It joined NATO in 2009, and when listed alphabetically among members of both alliances, Albania comes first. The Warsaw Pact was formed by the Soviet Union and its Eastern European satellite states as a counterbalance to NATO, which included Western European nations and North America aimed at deterring Soviet expansion. Over time, the shifting geopolitical landscape has seen the dissolution of the Warsaw Pact and the expansion of NATO, including former Warsaw Pact members such as Albania.