Answer:
B) Lead
Explanation:
The radioactive decay for iodine is:
₅₃I¹³¹ → ₋₁e⁰ + ₀γ⁰ + ₅₄Xe¹³¹
where 'e' and 'γ' represent the beta and gamma particles.
Gamma rays are more energetic and penetrating than beta rays. Lead is a metal that has a high density and atomic number which helps in blocking both gamma and beta rays.