There are four radioactive decay series called thorium (4n), uranium (4n + 2), actinium (4n + 3) and neptunium (4n + 1) series. Neptunium series is artifical while other three series are natural. End products of each radioactive decay series have stable nuclei. All natural decay series terminate at lead but neptunium or artificial series terminates at bismuth.
The starting isotope and the end product isotope of actinium series are:
A. `._(88)^(227)Ac` and `._(82)^(208)Pb`
B. `._(92)^(235)U` and `._(82)^(207)Pb`
C. `._(92)^(238)U` and `._(82)^(207)Pb`
D. `._(92)^(235)U` and `._(82)^(208)Pb`