李老汉与王老汉订了一买牛合同。李老汉向王老汉交付了两头牛，王老汉支付了相应价款，王老汉在宰杀该两头牛的过程中，发现一头牛中有牛黄，得款8 000元。关于该牛黄款的归属，以下正确的是 （）

A．归李老汉

B．归王老汉

C．由李老汉与王老汉按份共有

D．由李老汉与王老汉共同共有

It's important______the piano well.

A．of him to play

B．for him to play

C．of him playing

D．for him playing