all of the following radioisotopes are absorbed by bone tissue and tend to remain in the human body for a long time. Which of these isomers is probably the most hazardous to human health if it is taken internally, and which is the least hazardous? Explain your answer.

a$)$ Plutonium$-239($an alpha emitter$)$

b$)$ Strontium$-90($beta emitter$)$

c$)$ Metastable barium$-135($a gamma emitter$)$