To solve this problem, we need to understand how steroid hormones influence cellular activities. Let's analyze the options:$\newline \bullet$Option 1: Changing the permeability of the cell membrane$\newline$ - Steroid hormones are lipophilic and can easily pass through the cell membrane without altering its permeability.$\newline$ - Therefore, this option is incorrect.$\newline \bullet$Option 2: Binding to DNA and forming a gene-hormone complex$\newline$ - Steroid hormones pass through the cell membrane and bind to specific intracellular receptors.$\newline$ - The hormone-receptor complex then translocates to the nucleus, where it binds to specific DNA sequences.$\newline$ - This binding forms a gene-hormone complex that regulates the transcription of specific genes, influencing cellular activities.$\newline$ - Therefore, this option is correct.$\newline \bullet$Option 3: Activating cyclic AMP located on the cell membrane$\newline$ - Cyclic AMP (cAMP) is typically involved in the signaling pathways of peptide hormones, not steroid hormones.$\newline$ - Steroid hormones do not use cAMP as a second messenger.$\newline$ - Therefore, this option is incorrect.$\newline \bullet$Option 4: Using aquaporin channels as second messenger$\newline$ - Aquaporin channels are involved in water transport across cell membranes and are not related to steroid hormone signaling.$\newline$ - Therefore, this option is incorrect.$\newline$Based on the analysis, the correct option is Option 2: Binding to DNA and forming a gene-hormone complex.