Read the following statements and choose the correct option w.r.t. true and false statements.
(a) Sensory ganglion concerned with spinal reflex arc is located in ventral root of spinal cord.
(b) Spinal accessory and hypoglossal nerves are not cranial nerves in frog.
(c) Parasympathetic ganglia lie near or within the visceral organs.
(d) Sympathetic nerve fibres constitute the thoracico-lumbar outflow

Answer

To determine the truthfulness of the given statements regarding the nervous system, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (a)**: "Sensory ganglion concerned with spinal reflex arc is located in ventral root of spinal cord."
- **Analysis**: This statement is **False**. The sensory ganglion, which contains the cell bodies of sensory neurons, is actually located in the dorsal root of the spinal cord, not the ventral root. The ventral root contains motor neurons that exit the spinal cord to innervate muscles.

2. **Statement (b)**: "Spinal accessory and hypoglossal nerves are not cranial nerves in frog."
- **Analysis**: This statement is **False**. Both the spinal accessory nerve (cranial nerve XI) and the hypoglossal nerve (cranial nerve XII) are considered cranial nerves in frogs, as they arise from the brain and are involved in motor functions.

3. **Statement (c)**: "Parasympathetic ganglia lie near or within the visceral organs."
- **Analysis**: This statement is **True**. Parasympathetic ganglia are indeed located close to or within the organs they innervate, such as the heart, lungs, and digestive organs, allowing for localized control of organ function.

4. **Statement (d)**: "Sympathetic nerve fibres constitute the thoracico-lumbar outflow."
- **Analysis**: This statement is **True**. The sympathetic division of the autonomic nervous system is characterized by its thoracolumbar outflow, meaning that the sympathetic fibers originate from the thoracic and lumbar regions of the spinal cord.

### Summary of Statements:
- (a) False
- (b) False
- (c) True
- (d) True

### Final Answer:
- The correct options with respect to true and false statements are:
- (a) False
- (b) False
- (c) True
- (d) True