The most liquid asset among the options provided is cash.

Liquidity refers to the ease with which an asset can be converted into cash without incurring significant transaction costs or loss of value. In other words, it measures how quickly an asset can be bought or sold in the market.

Cash is considered the most liquid asset because it is readily accepted as a medium of exchange in most transactions. It is widely used for day-to-day transactions, such as purchasing goods and services, paying bills, or withdrawing money from an ATM. Cash can be easily and quickly converted into other forms of assets, such as goods, services, or financial instruments.

On the other hand, gold, shares, and land are less liquid assets compared to cash. Let's understand why:

1. Gold:
While gold is a highly valuable and widely traded commodity, it is not as liquid as cash. Selling gold may involve additional costs, such as commissions or fees, and it may take time to find a buyer who is willing to pay a fair price. The liquidity of gold also depends on the form in which it is held. Physical gold, such as bars or coins, may have lower liquidity compared to gold held in electronic form, such as exchange-traded funds (ETFs).

2. Shares:
Shares represent ownership in a company and can be bought or sold in the stock market. While shares are relatively liquid, their liquidity can vary depending on the trading volume and demand for the particular stock. Highly traded and popular stocks tend to be more liquid, meaning they can be easily bought or sold without significantly impacting the market price. However, less-traded or illiquid stocks may face challenges in finding buyers or sellers at a desired price.

3. Land:
Land is considered a less liquid asset compared to cash, gold, or shares. Selling land can be a time-consuming process that involves legal procedures, negotiations, and finding potential buyers. The liquidity of land also depends on factors such as location, market demand, and the purpose for which the land can be used. While land can be a valuable asset, converting it into cash quickly may not be feasible in certain situations.

In conclusion, cash is the most liquid asset among the options provided due to its wide acceptance, ease of use, and ability to be quickly converted into other forms of assets.