第1段的covering和以下哪个词意思最相近。
第1段开始写到,researchers最初发现捐赠者不排斥overhead(行政费用),只要他们知道其他人在支付这个费用就可以了。cover在这里的意思是to be enough money to pay for something,对应A funding: to provide the money to pay for an event, activity, or organization
B concealing: to prevent disclosure or recognition of 隐藏
C guarding: to protect from danger especially by watchful attention 保护
D managing: to handle or direct with a degree of skill 管理