Garrett was a commercial tour-boat operator on the northern coast of kauai, hawaii. he was licensed by the state of hawaii to operate his boat in hanalei bay. the u. s. department of transportation and the u. s. coast guard also granted garrett an unrestricted license to operate his boats in hanalei bay. hawaii subsequently passed a law that banned all commercial use of hanalei bay. the state refused to renew garrett's state license and ruled that he was not allowed to operate his vessel based on his federal licenses. garrett sued the state, alleging that the state law that prohibited him from operating his boat conflicted with the federal law that authorized him to do so. the court probably found that the state law was:
a. unconstitutional under the supremacy clause.
b. unconstitutional under the equal protection clause.
c. constitutional under the supremacy clause.
d. constitutional under the due process clause.