题干: 以下关于反向转换套利的说法中正确的有（ ）。

A．反向转换套利是先买进看涨期权，卖出看跌期权，再卖出一手期货合约的套利

B．反向转换套利中看涨期权与看跌期权的执行价格和到期月份必须相同

C．反向转换套利中期货合约与期权合约的到期月份必须相同

D．反向转换套利的净收益=（看跌期权权利金-看涨期权权利金）+（期货价格-期权价格执行价格）

One of the most convenient and cheapest ways to see America is by riding a Greyhound bus. This interstate bus system connects all major cities in the United States, (52) people with frequent and convenient service. The bus system even has an international service (53) makes connection with cities in Canada and Mexico.

Its network even extends to some of the smaller towns and out-of-the-way communities (54) the great interior of the country. Traveling by bus may (55) longer than flying by plane, but the terminals are located in the center of most cities and there is (56) to the downtown area. These buses are comfortable and air-conditioned. They are all equipped with toilets in the rear to (57) the convenience of the passengers, but there are some very severe (58) of conduct which are strictly enforced. On all buses (59) is forbidden and the consumption of alcoholic drinks is not allowed.

(60) bus travel may not be suited to everyone’s taste, it affords budget travelers the (61) to see America in comfort and safety and at a leisurely unhurried pace.

54().

A.for 

B.along 

C.in 

D.from