Which of the following parameter defines line type such as dashed and dotted?

pch stands for point character. It is a character string that specifies the type of point to be used to represent data points. The default value is 1, which is a circle. Other possible values include 2 (square), 3 (triangle), 4 (diamond), 5 (x), and 6 (plus sign).

lwd stands for line width. It is a numeric value that specifies the width of the line to be used. The default value is 1.

Therefore, the only parameter that defines line type is lty.