In 2002 some european countries threatened to deny permission to land airplanes for airlines that enjoy a government subsidy. the countries claimed that the threat was targeted against swissair, which was bailed out by the swiss government. however, it coincided with the u. s. imposing a tariff on steel imports and u. s. government compensation to the airlines for their losses due to the september 11th attack and increased security. such a threat by the europeans is an example
a) policies not allowed by wto.
b) the brander-spencer argument.
c) a desirable second-best outcome.
d) a trade policy that could lead to a trade war.