I rather say all of the above
But Iran's former leader made no bones of what he thinks about Israel and Israel by remote controlling USA tried its best to destroy Iran's Nuclear capability and was and still is thinking doing it Militarily
Saudi Arabia an important oil supplying ally also likes to destroy Iran and supports Syrians rebels so they can take over Damascus and create a hostile country in Iran's border and later support the export of trained rebels from Syria to Iran to overthrow the Iranian Govt and install a friendly puppet Govt who has control perhaps only in Tehran just like these countries did to Libya.
The new Iranian leader has thrown the Olive Branch but whether it will be taken is another matter.
The idea that the USA would be jealous of Iranian scientists is absurd. The only country that has any claim to its scientists making the USA jealous would be Germany. Iranian science is nowhere by comparison. How many Nobel Prizes in the sciences?
USA currently does not need Iranian oil, as the USA and Canada, with bits and pieces from mexico and further south supply the USA's needs. OTOH American oil companies would love to market everyone's oil for their own profits.
The USA is more or less friendly with a long list of Islamic countries.
You are correct on disrupting the balance of power!
Tjhe U.S. has plenty of oil without Iran.
The U.S. has superior scientists and more of them than Iran.
There are many U.S. citizens of all religions, including Islam.
Iran has not disprupted any balance of power.
The South Asia comment doesn't even make sense as stated.
Israel is not ruling over America and America is not reigning over any other country.
As for the real cause of hostility, check Empty's answer.
Because Persians have been a threat throughout history.
because they cant buy Iran's oil in peace
or they Jealous to Iran's scientist
or because Iran religion is Islam and USA is Atheist
or because Iran disrupted the balance of power
or because Iran is an important countries in South Asia
or because Israel ruling over American reign
or or or, what the hell is Real US hostility against Iran???
