Uranium `._(92)U^(238)` decayed to `._(82)Pb^(206)`. They decay process is `._(92)U^(238) underset((x alpha, y beta))(rarr ._(82)Pb^(206))` `t_(1//2)` of `U^(238) = 4.5 xx 10^(9)` years The analysis of a rock shows the relative number of `U^(238)` and `Pb^(206)` atoms `(Pb//U = 0.25)` The age of rock will beA. `(2.303)/(0.693) xx 4.5 xx 10^(9) log 1.25`B. `(2.303)/(0.693) xx 4.5 xx 10^(9) log 0.25`C. `(2.303)/(0.693) xx 4.5 xx 10^(9) log 4`D. `(2.303)/(4.5 xx 10^(9)) xx 0.693 log 4`