If \(\text{co}{{\text{s}}^{-1}}\left( \frac{2}{3\text{x}} \right)+\text{co}{{\text{s}}^{-1}}\left( \frac{3}{4\text{x}} \right)=\frac{\text{ }\!\!\pi\!\!\text{ }}{2}\left( \text{x}>\frac{3}{4} \right),\) then x is equal to:

• A. \(\frac{\sqrt{145}}{12}\)
• B. \(\frac{\sqrt{145}}{10}\)
• C. \(\frac{\sqrt{146}}{12}\)
• D. \(\frac{\sqrt{145}}{11}\)