Tìm nghiệm của phương trình sin 5x + cos^2 x - sin^2 x = 0

A. $\left[\begin{array}{l}\text{x}=-\frac{\text{π}}{6}+\text{k}\frac{\text{π}}{3}\\ \text{x}=-\frac{\text{π}}{14}+\text{k}\frac{\text{π}}{7}\end{array}\right.$

B. $\left[\begin{array}{l}\text{x}=-\frac{\text{π}}{6}+\text{k}\frac{\text{2π}}{3}\\ \text{x}=-\frac{\text{π}}{14}+\text{k}\frac{\text{2π}}{7}\end{array}\right.$

C. $\left[\begin{array}{l}\text{x}=\frac{\text{π}}{6}+\text{k2π}\\ \text{x}=\frac{\text{π}}{14}+\text{k2π}\end{array}\right.$

D. $\left[\begin{array}{l}\text{x}=-\frac{\text{π}}{6}+\text{k2π}\\ \text{x}=-\frac{\text{π}}{14}+\text{k2π}\end{array}\right.$