If \(\sin A=\frac{2}{5}\), where A " id="MathJax-Element-17-Frame" role="presentation" style="position: relative;" tabindex="0">A " id="MathJax-Element-70-Frame" role="presentation" style="position: relative;" tabindex="0">A " id="MathJax-Element-22-Frame" role="presentation" style="position: relative;" tabindex="0">A " id="MathJax-Element-19-Frame" role="presentation" style="position: relative;" tabindex="0">A
is an acute angle, what is the value of \(\frac{5 \sin A+2 \operatorname{cosec} A}{\sqrt{21} \sec A}\)?
1
\(\frac{5}{4}\)
2
\(\frac{7}{5}\)
3
\(\frac{4}{5}\)
4
\(\frac{5}{7}\)