Though no longer a series of colonies, the united states retains close ties to britain as
a. a commonwealth
b. a dependency
c. a dominion
d. part of a “special relationship”

Though no longer a series of colonies, the United States retains close ties to Britain as part of a "special relationship". So the correct option in regards to the given question is option "d". The main reason behind it is that United States and Britain share a common language, common laws, similar heritage, mutual dependence on open trades and similar types of businesses. These similarities have made them very close allies. They are dependent on each other militarily as well. The sync between the two nations are mainly based on military alliance and trading.

“destroyers for bases agreement in the destroyers for bases agreement between the united states and the united kingdom on september 2, 1940, fifty caldwell , wickes, and clemson class us navy destroyers were transferred to the toyalbnavy from the united states navy in exchange for land rights on british possessions.” i hope this you .