135
Correct option is A. 135
Mass defect Δm = 226.005 - 222.000 - 4.000= 0.005 amu
∴ Q value = 0.005 × 931.5 = 4.655 MeV
Also K.E_α + K.E_Rn = m_Rn/m_α × K.E_α = 4/222 × 4.44 = 0.08 MeV
∴ Energy of γ-Photon = 4.655 - (4.44 + 0.08)= 0.135 MeV = 135 KeV