The correct statements among (a) to (d) are
(a). Saline hyddrides produces `H_(2)` gas when reaction with `H_(2)O`.
(b). Reaction of `LiAlH_(4)` with `BF_(3)` leads to `B_(2)H_(6)`
(c). `PH_(3)` and `CH_(4)` are electron rich and electron precise hydrides, respectively.
(d). `HF` and `CH_(4)` are called as molecular hydrides.

Options

A. c and d only
B. a, c and d only
C. a, b, and c only
D. a, b, c and d only

Explanation

To determine the correct statements among (a) to (d), let's analyze each option step by step.

### Step 1: Analyze Option (a)
**Statement:** Saline hydrides produce `H2` gas when reacting with `H2O`.

**Explanation:**
Saline hydrides are ionic hydrides formed with alkali and alkaline earth metals. When saline hydrides react with water, they produce a metal hydroxide and hydrogen gas. For example, sodium hydride (NaH) reacts with water to produce sodium hydroxide (NaOH) and hydrogen gas (H2).
- **Reaction:** NaH + H2O → NaOH + H2

**Conclusion:** This statement is **correct**.

### Step 2: Analyze Option (b)
**Statement:** Reaction of `LiAlH4` with `BF3` leads to `B2H6`.

**Explanation:**
Lithium aluminum hydride (LiAlH4) reacts with boron trifluoride (BF3) to form diborane (B2H6). The reaction can be summarized as:
- **Reaction:** 2 LiAlH4 + 3 BF3 → B2H6 + 3 LiF + AlF3

**Conclusion:** This statement is **correct**.

### Step 3: Analyze Option (c)
**Statement:** `PH3` and `CH4` are electron-rich and electron-precise hydrides, respectively.

**Explanation:**
- **PH3 (Phosphine):** Phosphorus has a lone pair, making PH3 an electron-rich hydride.
- **CH4 (Methane):** Carbon in methane has four bonds and no lone pairs, making it an electron-precise hydride.

**Conclusion:** This statement is **correct**.

### Step 4: Analyze Option (d)
**Statement:** `HF` and `CH4` are called molecular hydrides.

**Explanation:**
Both HF (hydrogen fluoride) and CH4 (methane) are molecular compounds where hydrogen is covalently bonded to other elements (fluorine and carbon, respectively). They can be classified as molecular hydrides.

**Conclusion:** This statement is **correct**.

### Final Conclusion
All options (a), (b), (c), and (d) are correct.

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