To solve the question regarding which set of hormones are lipid-soluble and induce physiological responses by changing gene expression, we can follow these steps:
### Step 1: Understand Lipid-Soluble Hormones
Lipid-soluble hormones are typically steroid hormones or thyroid hormones. They can easily pass through cell membranes and bind to intracellular receptors, leading to changes in gene expression.
### Step 2: Analyze the Given Options
We need to evaluate each option to identify if all the hormones listed are lipid-soluble.
#### Option A: Estrogen, Thyroxin, and Cortisol
- **Estrogen**: A steroid hormone, lipid-soluble.
- **Thyroxin (T4)**: A thyroid hormone, lipid-soluble.
- **Cortisol**: A steroid hormone, lipid-soluble.
**Conclusion**: All three hormones in this option are lipid-soluble.
#### Option B: FSH, LH, and Testosterone
- **FSH (Follicle Stimulating Hormone)**: A glycoprotein hormone, not lipid-soluble.
- **LH (Luteinizing Hormone)**: A glycoprotein hormone, not lipid-soluble.
- **Testosterone**: A steroid hormone, lipid-soluble.
**Conclusion**: Not all hormones are lipid-soluble (FSH and LH are not).
#### Option C: Insulin, Oxytocin, and Estrogen
- **Insulin**: A peptide hormone, not lipid-soluble.
- **Oxytocin**: A peptide hormone, not lipid-soluble.
- **Estrogen**: A steroid hormone, lipid-soluble.
**Conclusion**: Not all hormones are lipid-soluble (Insulin and Oxytocin are not).
#### Option D: Estrogen, Relaxin, and Oxytocin
- **Estrogen**: A steroid hormone, lipid-soluble.
- **Relaxin**: A peptide hormone, not lipid-soluble.
- **Oxytocin**: A peptide hormone, not lipid-soluble.
**Conclusion**: Not all hormones are lipid-soluble (Relaxin and Oxytocin are not).
### Step 3: Identify the Correct Answer
After evaluating all options, the only set of hormones that are all lipid-soluble and can induce physiological responses by changing gene expression is **Option A: Estrogen, Thyroxin, and Cortisol**.
### Final Answer
**The correct answer is Option A: Estrogen, Thyroxin, and Cortisol.**
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