To solve this problem, we need to identify the period during which Mendel conducted his hybridization experiments.$\newline$Gregor Mendel, known as the father of genetics, conducted his famous experiments on pea plants to understand the inheritance of traits.$\newline$Let's analyze the given options:$\newline \bullet$Option 1: 1840–1850 - This period is too early for Mendel's experiments.$\newline \bullet$Option 2: 1857–1869 - This period overlaps with Mendel's work, but it extends beyond the actual years of his experiments.$\newline \bullet$Option 3: 1870–1877 - This period is after Mendel's experiments were completed.$\newline \bullet$Option 4: 1856–1863 - This period accurately represents the years during which Mendel conducted his hybridization experiments.$\newline$Mendel's experiments were conducted between 1856 and 1863, during which he meticulously cross-bred pea plants and recorded the inheritance patterns of various traits.$\newline$Therefore, the correct option is Option 4: 1856–1863.