The binomial theorem says that for any positive integer n, (a + b)ⁿ = nC0 * aⁿ + nC1 * aⁿ⁻¹ * b + nC2 * aⁿ⁻² * b² + ... + nCn * bⁿ. The rth term in the binomial expansion of (a + b)^n is: a) nCr - 1 * aⁿ - (r - 1) * bʳ⁻¹ b) nCr * aⁿ - r * bʳ c) nCr * aⁿ⁻ʳ * bʳ d) nCr - 1 * a⁽ⁿ⁻⁽ʳ⁻¹⁾* bʳ⁻¹