The increasing order of acidic nature of `Li_2O, BeO,B_2O_3,CuO` is :

Options

A. `Li_2Olt BeOltCuOltB_2O_3`
B. `BeOltCuOltB_2O_3ltLi_2O`
C. `Li_2Olt CuOltBeOltB_2O_3`
D. `B_2O_3lt CuOltBeOltLi_2O`

Explanation

To determine the increasing order of acidic nature of the oxides \(Li_2O\), \(BeO\), \(B_2O_3\), and \(CuO\), we can analyze the properties of these oxides based on their positions in the periodic table and their chemical behavior.

### Step-by-Step Solution:

1. **Identify the Nature of the Oxides**:
- \(Li_2O\) (Lithium oxide) is a basic oxide.
- \(BeO\) (Beryllium oxide) is amphoteric, meaning it can act as both an acid and a base.
- \(B_2O_3\) (Boron trioxide) is an acidic oxide.
- \(CuO\) (Copper(II) oxide) is a basic oxide.

2. **Understand the Trends in Acidic Nature**:
- As we move from left to right across a period in the periodic table, the metallic character decreases and the non-metallic character increases. This results in an increase in the acidic nature of the oxides.
- Basic oxides (like \(Li_2O\) and \(CuO\)) are less acidic, while acidic oxides (like \(B_2O_3\)) are more acidic.

3. **Rank the Oxides Based on Acidic Nature**:
- \(Li_2O\) is the most basic, hence it has the least acidic nature.
- \(CuO\) is also basic but less basic than \(Li_2O\), making it more acidic than \(Li_2O\).
- \(BeO\) is amphoteric and can act as an acid or a base, placing it in between \(CuO\) and \(B_2O_3\).
- \(B_2O_3\) is the most acidic among the given oxides.

4. **Final Order**:
- Based on the above analysis, the increasing order of acidic nature is:
\[ Li_2O < CuO < BeO < B_2O_3 \]

### Conclusion:
The increasing order of acidic nature of the oxides is:
\[ Li_2O < CuO < BeO < B_2O_3 \]