9. π⁺ represents a pion (a meson), μ represents a muon (a lepton), νₑ represents an electron neutrino (a lepton), and ν_μ represents a muon neutrino (a lepton). Which of the following decays might occur? (A) π⁺ → μ⁻ + ν̄_μ (B) π⁺ → μ⁺ + νₑ (C) π⁺ → μ⁺ + ν̄ₑ (D) π⁺ → μ⁺ + ν̄_μ (E) π⁺ → μ⁺ + ν_μ