Statement (i): India does indeed have a long coastline, bordered by the Indian Ocean to the south, the Arabian Sea to the west, and the Bay of Bengal to the east. This statement is correct.
Statement (ii): Indian coasts have a large number of well-developed sea ports, including major ports like Mumbai, Kolkata, Chennai, and Kandla, which facilitate significant international trade. This statement is correct.
Statement (iii): Although Kandla port is an important port for handling cargo in India, it does not specifically export huge amounts of iron-ore. Iron-ore is mostly exported through other ports like Vishakhapatnam and Paradip. Hence, this statement is incorrect.
Statement (iv): Transportation by water is indeed cost-effective, especially for voluminous goods such as bulk cargo, oil, and minerals, making this statement correct.
Thus, the correct statements are (i), (ii), and (iv), which makes option (A) the right choice.