The difference between the quoted buy and sell price of a stock is referred to as the spread of the stock. The average spread of the stocks is lowest on

For Monday:

Dabur: $462 - 460 = 2$

Marico: $346 - 345 = 1$

HUL: $1933 - 1931 = 2$

ITC: $238 - 237 = 1$

Britannia: $3046 - 3044 = 2$

Average spread = $\frac{2 + 1 + 2 + 1 + 2}{5} = 1.6$

For Tuesday:

Dabur: $458 - 455 = 3$

Marico: $336 - 335 = 1$

HUL: $1955 - 1952 = 3$

ITC: $239 - 238 = 1$

Britannia: $3101 - 3100 = 1$

Average spread = $\frac{3 + 1 + 3 + 1 + 1}{5} = 1.8$

For Thursday:

Dabur: $447 - 444 = 3$

Marico: $375 - 372 = 3$

HUL: $2048 - 2044 = 4$

ITC: $225 - 221 = 4$

Britannia: $3027 - 3025 = 2$

Average spread = $\frac{3 + 3 + 4 + 4 + 2}{5} = 3.2$

For Friday:

Dabur: $462 - 461 = 1$

Marico: $374 - 372 = 2$

HUL: $1969 - 1966 = 3$

ITC: $256 - 253 = 3$

Britannia: $3144 - 3140 = 4$

Average spread = $\frac{1 + 2 + 3 + 3 + 4}{5} = 2.6$

Comparing average spreads, the lowest average spread is on Monday at $1.6$, therefore Monday is the correct answer.