Hadrons that contain one or more strange quarks are called strange particles. The particles were originally called strange—before quark theory had been formulated—due to their anomalously long lifetimes of 10⁻¹⁰ to 10⁻⁷ s (compared with about 10⁻²³ to 10⁻²⁰ s for the other hadrons known at the time). When a strange hadron decays into particles that are not strange, the decay is a manifestation of the
(a) Strong interaction.
(b) Weak interaction.
(c) Electromagnetic interaction.
(d) Gravitational interaction.