When a uranium-235 nucleus takes in a neutron, it becomes unstable and splits by fission. This fission produces a barium (Ba) nucleus, a krypton (Kr) nucleus and 3 neutrons. The nuclear equation below shows the fission process. $^1_0\text{n} + ^{235}_{92}\text{U} \rightarrow ^{144}_{56}\text{Ba} + \;\text{Kr} + 3\,^1_0\text{n}$ Which symbol shows the krypton nucleus produced?
- A$^{89}_{36}\text{Kr}$
- B$^{91}_{34}\text{Kr}$
- C$^{91}_{35}\text{Kr}$
- D$^{91}_{36}\text{Kr}$