某物体的运动规律为<img src="https://nimg.ppkao.com/2019-04/wuacheng/2019042916473649609.jpg?sign=d7764eb551dc11538109dda54904a3f2&t=62d7cd53" />式中的k为大于零的常数。当t=0时,初速为v<sub>0</sub>,则速度v与时间t的函数关系是()<br /> <img src="https://nimg.ppkao.com/2019-04/wuacheng/2019042916474782081.jpg?sign=56903ecc11c426829008e8841385d7fe&t=62d7cd53" /><br /> <img src="https://nimg.ppkao.com/2019-04/wuacheng/2019042916475550549.jpg?sign=c32f83bc216a24da70454ea4bcbf90e4&t=62d7cd53" />
A、A
B、B
C、C
D、D