私は目的地に着くが(____)彼に電話した。
1. はやいか
2. はやるか
3. はやくて
4. はやめて
ANSWER (Highlight to read)
1
Explanation: A rough translation of 1 to 4 would be,
1. がはやいか is the same as やいなや. In otherwords "As soon as"
2. はやる could be
逸る 【はやる】 (v5r) to be in high spirits; to be impatient; to be hotblooded
or
流行る 【はやる】 (v5r) to flourish; to thrive; to be popular; to come into fashion
3. はやくて could be the connective, (-te) form of 早い / 速い.
4. はやめて could be the connective (-te) form of
早める(P); 速める(P) 【はやめる】 (v1) to hasten; to quicken; to expedite; to precipitate; to accelerate
Basically I chose '1' by a process of elimination. The sentence
"I phoned him as soon as I arrived at my destination." makes sense, the others either don't make sense (2) or have bad grammar (3,4).