Evaluate the triple iterated integral: \(\int_{-1}^{7} \int_{0}^{\frac{\pi}{2}} \int_{0}^{7} r\cos(\theta) \, dr \, d\theta \, dz\)
What is the value of the triple iterated integral?

A) \(0\)
B) \(\frac{7\pi}{4}\)
C) \(\frac{49\pi}{4}\)
D) \(\frac{14\pi}{4}\)