To solve this problem, we need to identify which phytohormone, when sprayed on juvenile conifers, accelerates their maturity and leads to early seed production. Let's analyze each option:$\newline \bullet$Indole-3-butyric acid:$\newline$ - This is an auxin, primarily involved in root initiation and growth. It is not typically associated with hastening maturity in conifers.$\newline \bullet$Gibberellic Acid:$\newline$ - Gibberellic acid (GA) is a well-known plant hormone that promotes growth and development. It is particularly effective in breaking dormancy and promoting flowering and seed production.$\newline$ - Spraying gibberellic acid on juvenile conifers can indeed hasten their maturity, leading to early seed production.$\newline \bullet$Zeatin:$\newline$ - Zeatin is a type of cytokinin, which primarily promotes cell division and growth. It is not specifically known for hastening maturity in conifers.$\newline \bullet$Abscisic Acid:$\newline$ - Abscisic acid (ABA) is involved in stress responses and seed dormancy. It generally inhibits growth and is not used to hasten maturity.$\newline$Based on the analysis, gibberellic acid is the phytohormone that helps in hastening the maturity period of juvenile conifers, leading to early seed production.$\newline$Therefore, the correct option is Option 2: Gibberellic Acid.